Early Postoperative Effects of Cataract Surgery on Anterior Segment Parameters in Primary Open-Angle Glaucoma and Pseudoexfoliation Glaucoma

Evaluation of changes of anterior segment parameters in patients with pseudoexfoliation syndrome after cataract surgery using anterior segment optical coherence tomography

The aim of the study was to compare the anterior segment parameters after cataract surgery in pseudoexfoliation syndrome (PEX) and control eyes. We conducted a prospective comparative study of 36 eyes (PEX group), 16 eyes (PEXG group) and 46 eyes (control group) of 98 patients after phacoemulsification with intraocular lens implantation. Before surgery, 1 week, 1 month and 3 months postoperatively, anterior chamber parameters were evaluated by swept source anterior segment optical coherence tomography (AS-OCT). Anterior chamber depth (ACD), angle opening distance (AOD500/750), trabecular-iris space area (TISA500/750), trabecular-iris angle (TIA500/750) and lens vault (LV) were assessed at each study visit. Preoperatively, ACD, AOD500/750 and TISA500/750 were significantly smaller, while LV was significantly greater in PEX and PEXG eyes than in controls. 3 months postoperatively all irido-corneal parameters and ACD were significantly greater in all study groups without intergroup differences. ACD and LV significantly increased in PEX group between 1 and 3 months after surgery while being stable in control group. Relative increases in ACD, AOD500, TISA750, TIA500/750 were significantly higher in PEX and PEXG groups than in controls. Our study finds that ACD and iridocorneal parameters in AS-OCT demonstrated significantly greater relative increases 3 months after phacoemulsification in PEX and PEXG groups than in control eyes. Significantly greater deepening of anterior chamber and opening of the irido-corneal angle may be a reason for different refractive outcomes and IOP control in patients with PEX and PEXG after routine cataract surgery.

The effect of uneventful cataract surgery on Schlemm's canal and the trabecular meshwork in cases with pseudoexfoliation

PURPOSE

To evaluate the effect of uneventful cataract surgery on Schlemm's canal (SC) and the trabecular meshwork (TM) in cases with pseudoexfoliation (PX).

METHODS

In this prospective study, 37 PX and 37 normal eyes, who underwent cataract surgery, were included. The PX group was further divided into two subgroups: PX syndrome (PXS) and PX glaucoma (PXG). Preoperative complete ophthalmologic examination, anterior segment (AS) imaging using a Scheimpflug camera, and measurements of SC length and area and TM thickness and length using AS optical coherence tomography (AS-OCT) were performed in all cases. All measurements were repeated at the first and third months after surgery.

RESULTS

Preoperative intraocular pressure (IOP), AS parameters, SC, and TM values showed no significant differences between the groups (p > 0.05). After surgery, there was a significant increase in AS parameter values and a significant decrease in IOP values in both the PX and control groups (p < 0.05). The nasal and temporal SC area showed a significant increase in the PX group after surgery (p = 0.007, p = 0.003, respectively). In the subgroup analysis, the only significant change in the nasal and temporal SC area was in the PXS group (p = 0.006, p = 0.003, respectively).

CONCLUSION

Cataract surgery resulted in an increase in the SC area in patients with PXS. This increase may be due to multiple mechanisms including the IOP-lowering effect of cataract removal, change in AS, and removal of intraocular PX material after surgery.

Predictors of intraocular pressure change after cataract surgery in patients with pseudoexfoliation glaucoma and in nonglaucomatous patients

Background/Aim. The cataract surgery in eyes with and without glaucoma results in the sustained intraocular pressure (IOP) reduction but it is still unknown which glaucomatous patients will achieve clinically significant reduction. The preoperative IOP and some ocular biometric parameters have been shown as potential predictors of the postoperative IOP reduction. The aim of our prospective intervention study was to evaluate that relationship in medically controlled patients with the pseudoexfoliation glaucoma (PXG) and in the nonglaucomatous patients. Methods. Thirty-one PXG patients (31 eyes) and 31 nonglaucomatous patients (31 eyes), all with clinically significant cataract, were enrolled. The preoperative IOP, anterior chamber depth (ACD), axial length (AL), lens thickness (LT), lens position (LP) [LP = ACD + 0.5 LT], relative lens position (RLP) [RLP = LP / AL] and the pressure-to-depth ratio (PD ratio) [PD ratio = preoperative IOP/preoperative ACD] were evaluated as potential predictors of the IOP change in the 6th postoperative month. Results. In the 6th postoperative month, in the PXG group, the IOP reduction was -3.23 ? 3.41 mmHg (-17.67 ? 16.86%) from the preoperative value of 16.27 ? 3.08 mmHg and in the control group, the reduction was -2.26 ? 1.71 mmHg (-15.06 ? 10.93%) from the preoperative value of 14.53 ? 2.04 mmHg. In the PXG group, the significant predictors of the absolute and the percentage IOP reduction were the preoperative IOP, AL, and PD ratio. In the same group, RLP was shown as a significant predictor of absolute change in the IOP in multi-variate analysis, and the percentage IOP change in both the univariate and the multivariate analyses. In the control group, the preoperative IOP and the PD ratio were the only significant parameters that could predict absolute change in the postoperative IOP. Conclusion. The cataract surgery leads to the IOP reduction both in the PXG and nonglaucomatous eye. Predictors monitored in this study are widely available and simply calculable parameters that can be potentially used in managing glaucoma.

Nasal trabeculo-ciliary angle and relative lens vault as predictors for intraocular pressure reduction following phacoemulsification

PURPOSE

To evaluate quantitative relationships between biometric measurements and expected intraocular pressure reduction following phacoemulsification.

DESIGN

A prospective, comparative clinical study.

METHODS

Forty nine candidates for phacoemulsification were included. Intraocular pressure was measured preoperatively and after 7 and 30 days. Ocular biometrics were measured using optical biometry and ultrasound biomicroscopy preoperatively and 1 month postoperatively.

RESULTS

Patients were sub-grouped into open-angle glaucoma (12 eyes), angle-closure glaucoma (18 eyes), and cataract-only groups (19 eyes). The mean intraocular pressure reduction was -1.67 ± 2.73, -13.11 ± 7.98, and -7.50 ± 3.58 mmHg in the cataract-only, angle-closure glaucoma, and open-angle glaucoma groups (p = 0.001). The delta-intraocular pressure at day 7 showed positive correlations with lens vault and relative-lens vault (p = 0.005 and 0.001). It showed negative correlations with lens position, relative-lens position, anterior chamber depth, aqueous depth, and nasal and temporal angles in addition to lens thickness, anterior vault, nasal trabeculo-ciliary angle, and temporal-trabeculo-ciliary angle at the end of the follow-up period. Regression analysis revealed significant associations between preoperative intraocular pressure and both nasal-trabeculo-ciliary angle and anterior vault (p = 0.038 and 0.019) and delta-intraocular pressure and both nasal-trabeculo-ciliary angle and relative-lens vault (p = 0.001 and ≤0.001) with an area under the curve of 0.71 for relative-lens vault. For every degree decrease in nasal-trabeculo-ciliary angle, there was an expected 0.33 mmHg intraocular pressure reduction with no expected change if nasal-trabeculo-ciliary angle decreased to <22°.

CONCLUSIONS

The relationship between anterior-segment-biometrics could determine intraocular pressure behavior after phacoemulsification. The preoperative nasal-trabeculo-ciliary angle and relative-lens vault could be significant predictors for postoperative intraocular pressure reduction.

Comparison of Refractive Status and Anterior Segment Parameters of Juvenile Open-Angle Glaucoma and Normal Subjects

Objectives:

Our aim was to compare the refractive status and anterior segment parameters of patients with juvenile open-angle glaucoma (JOAG) and normal subjects.

Materials and Methods:

Twenty-five recently diagnosed cases of JOAG and 24 normal subjects were included in this prospective controlled clinical trial. Central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT), axial length (AL), K1 and K2 keratometry, and white-to-white distance (WTW) measurements were performed with optical biometry (LenStar LS 900, Haag Streit Diagnostics). Spherical equivalent (SE) values and anterior segment parameters were statistically compared by chi-square, Kolmogorov- Smirnov, and independent samples t-tests.

Results:

The mean age of the 15 male and 10 female JOAG patients was 11.8±2.78 (8-18) years and the mean age of the 14 male and 10 female normal subjects was 11.58±3.04 (7-16) years (age: p=0.51; sex: p=0.18). Mean intraocular pressure in the JOAG group before treatment was 30.08±4.3 mmHg. The mean SE values of the JOAG and the control group were -1.94±1.86 (+2.35/-5.5) and -0.76±2.03 (+2.25/-4.85) diopters, respectively (p=0.048). JOAG patients had lower mean CCT values (p=0.016) and higher mean AL and ACD values (p=0.049 and p=0.016). There were no significant differences between the groups for LT, WTW, K1, or K2 (p=0.61; p=0.52; p=0.95; p=0.31 respectively).

Conclusion:

JOAG patients were found to be more myopic and have lower CCT and greater AL and ACD values than normal subjects. These anterior segment changes may be associated with myopia, which is common in JOAG.

Effect of phacoemulsification on intraocular pressure in patients with primary open angle glaucoma and pseudoexfoliation glaucoma

AIM

To compare the effect of phacoemulsification on intraocular pressure (IOP) in patients with primary open angle glaucoma (POAG) and pseudoexfoliation glaucoma (PXG).

METHODS

A retrospective comparative case series conducted at the Glaucoma Department at the Association to Prevent Blindness in Mexico. The study enrolled consecutive patients having phacoemulsification with intraocular lens (IOL) implantation and a diagnosis of POAG or PXG. Data about IOP values and number of glaucoma medications used was collected at baseline, 1, 3, 6 and 12mo postoperatively.

RESULTS

The study enrolled 88 patients (88 eyes). After phacoemulsification, there was a statistically significant reduction in IOP values and glaucoma medications use compared to baseline in both POAG and PXG patients (P<0.001). In the POAG group, a 20% decrease in IOP values was evidenced, and a 56.5% reduction in the number of medications used at the one-year follow-up. The PXG group showed a 20.39%, and a 34.46% decrease in IOP and number of medications used, respectively. A significant difference in the mean ΔIOP (postoperative changes in IOP) was evidenced between groups (P=0.005). The reduction of the postsurgical IOP mean values in both groups, the POAG group showed a greater reduction in IOP values compared to the PXG group.

CONCLUSION

In both types of glaucoma, phacoemulsification cataract surgery can result in a significant IOP reduction (20%) over a 12mo follow-up period. The number of medications used is also significantly reduced up to 12mo after surgery, especially in the PXG group.